Effect of antimony content on electrical and structural properties of 0.98(K0.48Na0.52)0.95Li0.05Nb1−xSbxO3–0.02Ba0.5(Bi0.5Na0.5)0.5ZrO3 ceramics

Abstract

Lead-free 0.98(K0.48Na0.52)0.95Li0.05Nb1−xSbxO3–0.02Ba0.5(Bi0.5Na0.5)0.5ZrO3 (KNLNSx–BBNZ) solid solution with 0.04<x<0.08 was prepared by traditional solid-state process. Samples were sintered using a conventional method at 1120°C for 4h. The effect of Sb5+ content on the phase structure, microstructure, ferroelectric, dielectric and piezoelectric properties of the KNLNSx–BBNZ ceramics was studied. The phase transition of the ceramic was determined by the temperature dependence of the dielectric properties, while the structural properties, like the phase coexistence, were studied by X-ray diffraction. It was found that ceramics in the composition range of 0.06<x<0.08 possess an orthorhombic (Amm2) and tetragonal (P4mm) phases coexistence. The best piezoelectric properties were obtained in the ceramics with x=0.07: d33=282pC/N, −d31=103pC/N, kp=46%, ɛr=1820, tanδ=3% and Tc=271°C. Furthermore, this composition exhibited a good thermal stability, up to 200°C on d33 piezoelectric constant, indicating that this material have great potential for application from room temperature until this temperature limit.